That Robot and Robot Look ...:

In addition the BBC announced two additional cast members today, comedy duo David Mitchell and Robert Webb, who will provide the voice of the two robots in the episode - the former of which keen listeners recognised in the trailer!

Executive producer Caroline Skinner said: "We were thrilled to have David Mitchell and Robert Webb on board. It's a huge adventure, a real no-holds-barred belter of an episode and having them voice these two incredible-looking robots was just perfect. It makes them funny and chilling and… But I can’t say too much now except we’re all delighted with the episode!"